* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    font-family: 'Microsoft YaHei', 'PingFang SC', sans-serif;
    font-size: 14px;
    line-height: 1.5;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 全局导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    width: 180px;
    height: 45px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: bold;
    color: #1a365d;
    text-decoration: none;
    transition: opacity 0.3s ease;
}

.logo:hover {
    opacity: 0.8;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links li a {
    text-decoration: none;
    color: #333;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links li a:hover {
    color: #2563eb;
}

.auth-buttons {
    display: flex;
    gap: 15px;
}

.btn {
    padding: 8px 20px;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background-color: #1e40af;
    color: #fff;
}

.btn-primary:hover {
    background-color: #1d4ed8;
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: transparent;
    color: #1e40af;
    border: 1px solid #1e40af;
}

.btn-secondary:hover {
    background-color: #e0e7ff;
}

.menu-toggle {
    display: none;
    font-size: 24px;
    cursor: pointer;
    color: #333;
}

/* Banner样式 */
.banner {
    margin-top: 70px;
    width: 100%;
    height: 420px;
    background: linear-gradient(135deg, #1e3a5f 0%, #2d5a87 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.banner::before {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    width: 50%;
    height: 100%;
    background: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" width="400" height="400" viewBox="0 0 400 400"%3E%3Ccircle cx="200" cy="200" r="100" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/%3E%3Ccircle cx="200" cy="200" r="150" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="1"/%3E%3C/svg%3E') no-repeat center center;
    background-size: cover;
}

.banner-content {
    max-width: 1200px;
    width: 100%;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

.banner-title {
    font-size: 42px;
    font-weight: bold;
    color: #fff;
    margin-bottom: 20px;
    animation: fadeInUp 0.6s ease;
}

.banner-subtitle {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 30px;
    animation: fadeInUp 0.6s ease 0.2s;
    animation-fill-mode: both;
}

.banner-btn {
    padding: 12px 30px;
    font-size: 16px;
    animation: fadeInUp 0.6s ease 0.4s;
    animation-fill-mode: both;
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* 平台优势模块 */
.advantages {
    padding: 60px 0;
    background-color: #fff;
}

.section-title {
    text-align: center;
    font-size: 28px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 50px;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.advantage-card {
    background-color: #f8fafc;
    border-radius: 10px;
    padding: 30px;
    text-align: center;
    transition: all 0.3s ease;
}

.advantage-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.advantage-icon {
    width: 120px;
    height: 120px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 48px;
    transition: box-shadow 0.3s ease;
}

.advantage-card:hover .advantage-icon {
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.4);
}

.advantage-title {
    font-size: 18px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 10px;
}

.advantage-desc {
    font-size: 14px;
    color: #666;
    line-height: 1.6;
}

/* 热门课程模块 */
.courses {
    padding: 60px 0;
    background-color: #f5f5f5;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.course-card {
    background-color: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.course-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.course-cover {
    width: 100%;
    height: 160px;
    overflow: hidden;
    transition: transform 0.3s ease;
}

.course-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 6px;
}

.course-card:hover .course-cover {
    transform: scale(1.03);
}

.course-info {
    padding: 20px;
}

.course-title {
    font-size: 16px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 8px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.course-target {
    font-size: 13px;
    color: #666;
    margin-bottom: 8px;
}

.course-desc {
    font-size: 13px;
    color: #888;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 师资优势模块 */
.teachers {
    padding: 60px 0;
    background-color: #fff;
}

.teacher-content {
    display: flex;
    align-items: center;
    gap: 60px;
}

.teacher-image {
    width: 400px;
    height: 260px;
    background: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 48px;
    animation: fadeIn 0.6s ease;
}

.teacher-info {
    flex: 1;
    animation: fadeIn 0.6s ease 0.2s;
    animation-fill-mode: both;
}

.teacher-title {
    font-size: 24px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 20px;
}

.teacher-desc {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
    margin-bottom: 15px;
}

/* 课程专区页面 */
.course-section-banner {
    margin-top: 70px;
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #1e3a5f 0%, #2d5a87 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.course-section-banner::before {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    width: 50%;
    height: 100%;
    background: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" width="300" height="300" viewBox="0 0 300 300"%3E%3Ccircle cx="150" cy="150" r="80" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/%3E%3C/svg%3E') no-repeat center center;
    background-size: cover;
}

.course-section-content {
    max-width: 1200px;
    width: 100%;
    padding: 0 20px;
    position: relative;
    z-index: 1;
    text-align: center;
}

.course-section-title {
    font-size: 32px;
    font-weight: bold;
    color: #fff;
    margin-bottom: 25px;
}

.category-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
}

.category-btn {
    padding: 10px 25px;
    background-color: rgba(255, 255, 255, 0.2);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 14px;
}

.category-btn:hover,
.category-btn.active {
    background-color: #fff;
    color: #1e3a5f;
}

.course-list {
    padding: 40px 0;
}

.course-list-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.course-list-card {
    background-color: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.course-list-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.course-list-cover {
    width: 100%;
    height: 170px;
    overflow: hidden;
    transition: transform 0.3s ease;
}

.course-list-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 6px;
}

.course-list-card:hover .course-list-cover {
    transform: scale(1.03);
}

.course-list-info {
    padding: 20px;
}

.course-list-title {
    font-size: 16px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 8px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.course-list-scene {
    font-size: 13px;
    color: #666;
    margin-bottom: 8px;
}

.course-list-highlight {
    font-size: 13px;
    color: #2563eb;
    margin-bottom: 8px;
}

.course-list-teacher {
    font-size: 12px;
    color: #888;
    margin-bottom: 12px;
}

.course-list-price {
    font-size: 20px;
    font-weight: bold;
    color: #dc2626;
}

/* 课程详情页 */
.course-detail-header {
    margin-top: 70px;
    padding: 40px 0;
    background-color: #fff;
}

.course-detail-banner {
    width: 100%;
    max-width: 1200px;
    height: 380px;
    margin: 0 auto 30px;
    border-radius: 10px;
    overflow: hidden;
}

.course-detail-banner img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.course-detail-info {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.course-detail-title {
    font-size: 28px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 15px;
}

.course-detail-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 20px;
}

.meta-item {
    font-size: 14px;
    color: #666;
}

.meta-item span {
    font-weight: bold;
    color: #333;
}

.course-detail-desc {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
}

.course-detail-content {
    padding: 40px 0;
    background-color: #f5f5f5;
}

.content-section {
    max-width: 1200px;
    margin: 0 auto 40px;
    padding: 0 20px;
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
}

.content-section-title {
    font-size: 22px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 20px;
}

.content-row {
    display: flex;
    gap: 40px;
    align-items: center;
}

.content-text {
    flex: 1;
    font-size: 15px;
    color: #666;
    line-height: 1.8;
}

.content-image {
    width: 450px;
    height: 280px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 32px;
}

.content-text ul {
    list-style: none;
    padding-left: 0;
}

.content-text ul li {
    padding: 8px 0;
    position: relative;
    padding-left: 20px;
}

.content-text ul li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #22c55e;
    font-weight: bold;
}

/* 付费下载悬浮区 */
.purchase-float {
    position: fixed;
    bottom: 80px;
    right: 20px;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    padding: 20px 25px;
    z-index: 999;
    min-width: 280px;
}

.purchase-price {
    font-size: 24px;
    font-weight: bold;
    color: #dc2626;
    margin-bottom: 15px;
}

.purchase-btn {
    width: 100%;
    padding: 12px;
    font-size: 16px;
}

.download-btn {
    background-color: #22c55e;
    color: #fff;
}

.download-btn:hover {
    background-color: #16a34a;
}

/* 会员中心 */
.member-center {
    margin-top: 70px;
    padding: 40px 0;
    background-color: #f5f5f5;
    min-height: calc(100vh - 70px);
}

.member-header {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    gap: 30px;
}

.member-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 32px;
    border: 3px solid #e0e7ff;
    transition: border-color 0.3s ease;
}

.member-avatar:hover {
    border-color: #3b82f6;
}

.member-info h2 {
    font-size: 20px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 5px;
}

.member-info p {
    font-size: 14px;
    color: #666;
}

.member-menu {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 30px;
}

.menu-item {
    background-color: #fff;
    border-radius: 10px;
    padding: 25px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.menu-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.menu-icon {
    width: 40px;
    height: 40px;
    margin: 0 auto 15px;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 20px;
}

.menu-title {
    font-size: 14px;
    font-weight: 500;
    color: #333;
}

.member-purchased {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
}

.purchased-title {
    font-size: 18px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 20px;
}

.purchased-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.purchased-card {
    border: 1px solid #e5e7eb;
    border-radius: 10px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.purchased-card:hover {
    border-color: #3b82f6;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.2);
}

.purchased-cover {
    width: 100%;
    height: 120px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 24px;
}

.purchased-info {
    padding: 15px;
}

.purchased-title-text {
    font-size: 14px;
    font-weight: 500;
    color: #333;
    margin-bottom: 10px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.purchased-actions {
    display: flex;
    gap: 10px;
}

.purchased-btn {
    flex: 1;
    padding: 6px 10px;
    font-size: 12px;
    text-align: center;
}

/* 登录/注册页面 */
.login-page {
    min-height: 100vh;
    background: linear-gradient(135deg, #1e3a5f 0%, #2d5a87 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-container {
    background-color: #fff;
    border-radius: 15px;
    overflow: hidden;
    display: flex;
    max-width: 900px;
    width: 100%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.login-image {
    width: 350px;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 48px;
}

.login-form {
    flex: 1;
    padding: 40px;
}

.form-title {
    font-size: 24px;
    font-weight: bold;
    color: #1a365d;
    text-align: center;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: #333;
    margin-bottom: 8px;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #3b82f6;
}

.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    font-size: 13px;
}

.form-options a {
    color: #3b82f6;
    text-decoration: none;
}

.form-options a:hover {
    text-decoration: underline;
}

.login-btn {
    width: 100%;
    padding: 14px;
    font-size: 16px;
}

.form-switch {
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
    color: #666;
}

.form-switch a {
    color: #3b82f6;
    text-decoration: none;
}

.form-switch a:hover {
    text-decoration: underline;
}

/* 关于我们页面 */
.about-page {
    margin-top: 70px;
    min-height: calc(100vh - 70px);
}

.about-banner {
    width: 100%;
    height: 220px;
    background: linear-gradient(135deg, #1e3a5f 0%, #2d5a87 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.about-banner::before {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    width: 50%;
    height: 100%;
    background: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" width="300" height="300" viewBox="0 0 300 300"%3E%3Ccircle cx="150" cy="150" r="80" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/%3E%3C/svg%3E') no-repeat center center;
    background-size: cover;
}

.about-banner-title {
    font-size: 32px;
    font-weight: bold;
    color: #fff;
    position: relative;
    z-index: 1;
}

.about-content {
    padding: 40px 0;
    background-color: #fff;
}

.about-section {
    max-width: 1200px;
    margin: 0 auto 40px;
    padding: 0 20px;
}

.about-section:last-child {
    margin-bottom: 0;
}

.about-section-title {
    font-size: 22px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 20px;
}

.about-section-text {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
    margin-bottom: 20px;
}

.about-image {
    max-width: 800px;
    height: 300px;
    margin: 0 auto;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 32px;
}

/* 合规公示页面 */
.compliance-page {
    margin-top: 70px;
    padding: 40px 0;
    background-color: #fff;
    min-height: calc(100vh - 70px);
}

.compliance-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

.compliance-title {
    font-size: 24px;
    font-weight: bold;
    color: #1a365d;
    text-align: center;
    margin-bottom: 30px;
}

.compliance-content {
    font-size: 15px;
    color: #333;
    line-height: 2;
    text-align: justify;
}

.compliance-content h2 {
    font-size: 18px;
    font-weight: bold;
    color: #1a365d;
    margin: 25px 0 15px;
}

.compliance-content h3 {
    font-size: 16px;
    font-weight: bold;
    color: #333;
    margin: 20px 0 10px;
}

.compliance-content p {
    margin-bottom: 15px;
}

.compliance-content ul {
    padding-left: 20px;
    margin-bottom: 15px;
}

.compliance-content li {
    margin-bottom: 8px;
}

/* 全局底部 */
.footer {
    background-color: #1a365d;
    padding: 30px 0;
    color: #fff;
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 13px;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: #fff;
}

.footer-info {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 10px;
}

.footer-contact {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 10px;
}

.footer-record {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.6);
}

.footer-record a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
}

.footer-record a:hover {
    color: #fff;
}

/* 支付成功弹窗 */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.modal-overlay.show {
    display: flex;
}

.modal {
    background-color: #fff;
    border-radius: 15px;
    padding: 40px;
    text-align: center;
    max-width: 400px;
    width: 90%;
    animation: fadeInUp 0.3s ease;
}

.modal-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 40px;
}

.modal-title {
    font-size: 22px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 10px;
}

.modal-desc {
    font-size: 14px;
    color: #666;
    margin-bottom: 25px;
}

.modal-btn {
    padding: 10px 30px;
}

/* 帮助中心页面 */
.help-center {
    margin-top: 70px;
    padding: 40px 0;
    background-color: #f5f5f5;
    min-height: calc(100vh - 70px);
}

.help-center-banner {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #1e3a5f 0%, #2d5a87 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    margin-bottom: 40px;
}

.help-center-banner::before {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    width: 50%;
    height: 100%;
    background: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" width="300" height="300" viewBox="0 0 300 300"%3E%3Ccircle cx="150" cy="150" r="80" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/%3E%3C/svg%3E') no-repeat center center;
    background-size: cover;
}

.help-center-title {
    font-size: 32px;
    font-weight: bold;
    color: #fff;
    position: relative;
    z-index: 1;
}

.help-categories {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 40px;
}

.help-category {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.help-category:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    border-color: #3b82f6;
}

.help-category-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 15px;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 24px;
}

.help-category-title {
    font-size: 18px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 10px;
}

.help-category-desc {
    font-size: 14px;
    color: #666;
}

.help-content {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
}

.help-content-title {
    font-size: 22px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 20px;
}

.help-list {
    list-style: none;
    padding-left: 0;
}

.help-list li {
    padding: 15px 0;
    border-bottom: 1px solid #e5e7eb;
    position: relative;
    padding-left: 25px;
}

.help-list li:last-child {
    border-bottom: none;
}

.help-list li::before {
    content: '📌';
    position: absolute;
    left: 0;
    font-size: 14px;
}

.help-list li a {
    color: #333;
    text-decoration: none;
    font-size: 15px;
    transition: color 0.3s ease;
}

.help-list li a:hover {
    color: #2563eb;
}

/* FAQ页面 */
.faq-page {
    margin-top: 70px;
    padding: 40px 0;
    background-color: #f5f5f5;
    min-height: calc(100vh - 70px);
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

.faq-title {
    text-align: center;
    font-size: 28px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 40px;
}

.faq-item {
    background-color: #fff;
    border-radius: 10px;
    margin-bottom: 15px;
    overflow: hidden;
}

.faq-question {
    padding: 20px 25px;
    background-color: #f8fafc;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 16px;
    font-weight: 500;
    color: #1a365d;
    transition: background-color 0.3s ease;
}

.faq-question:hover {
    background-color: #e0e7ff;
}

.faq-question::after {
    content: '+';
    font-size: 24px;
    color: #666;
    transition: transform 0.3s ease;
}

.faq-item.active .faq-question::after {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 25px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item.active .faq-answer {
    padding: 20px 25px;
    max-height: 500px;
}

.faq-answer p {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
}

/* 联系我们页面 */
.contact-page {
    margin-top: 70px;
    padding: 40px 0;
    background-color: #f5f5f5;
    min-height: calc(100vh - 70px);
}

.contact-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

.contact-title {
    text-align: center;
    font-size: 28px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 40px;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.contact-info {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
}

.contact-info-title {
    font-size: 20px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 25px;
}

.contact-detail {
    margin-bottom: 20px;
}

.contact-detail-icon {
    display: inline-block;
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 18px;
    margin-right: 15px;
    vertical-align: middle;
}

.contact-detail-text {
    display: inline-block;
    vertical-align: middle;
    font-size: 15px;
    color: #333;
}

.contact-form {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
}

.contact-form-title {
    font-size: 20px;
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 25px;
}

.contact-form-group {
    margin-bottom: 20px;
}

.contact-form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: #333;
    margin-bottom: 8px;
}

.contact-form-group input,
.contact-form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s ease;
}

.contact-form-group input:focus,
.contact-form-group textarea:focus {
    outline: none;
    border-color: #3b82f6;
}

.contact-form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.contact-submit-btn {
    width: 100%;
    padding: 14px;
    font-size: 16px;
}

/* 搜索功能 */
.search-bar {
    margin-bottom: 30px;
    text-align: center;
}

.search-input {
    width: 50%;
    max-width: 500px;
    padding: 12px 20px;
    border: 1px solid #e5e7eb;
    border-radius: 25px;
    font-size: 15px;
    background-color: #fff;
    transition: border-color 0.3s ease;
}

.search-input:focus {
    outline: none;
    border-color: #3b82f6;
}

/* 学员评价模块 */
.testimonials {
    padding: 60px 0;
    background-color: #f5f5f5;
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.testimonial-card {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
    position: relative;
}

.testimonial-card::before {
    content: '"';
    font-size: 48px;
    color: #e0e7ff;
    position: absolute;
    top: 20px;
    right: 20px;
}

.testimonial-content {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
    margin-bottom: 20px;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 15px;
}

.testimonial-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 20px;
}

.testimonial-info {
    font-size: 14px;
}

.testimonial-name {
    font-weight: bold;
    color: #1a365d;
    margin-bottom: 3px;
}

.testimonial-role {
    color: #666;
}

/* 数据统计模块 */
.stats {
    padding: 60px 0;
    background: linear-gradient(135deg, #1e3a5f 0%, #2d5a87 100%);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.stat-item {
    text-align: center;
    color: #fff;
}

.stat-number {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 16px;
    color: rgba(255, 255, 255, 0.8);
}

/* 响应式适配 */
@media (max-width: 1024px) {
    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .courses-grid,
    .course-list-grid,
    .purchased-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .teacher-content {
        flex-direction: column;
        text-align: center;
    }
    
    .teacher-image {
        width: 100%;
        max-width: 400px;
    }
    
    .content-row {
        flex-direction: column;
    }
    
    .content-image {
        width: 100%;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background-color: #fff;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    }
    
    .nav-links.show {
        display: flex;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .advantages-grid,
    .courses-grid,
    .course-list-grid,
    .member-menu,
    .purchased-grid {
        grid-template-columns: 1fr;
    }
    
    .banner-title {
        font-size: 28px;
    }
    
    .banner-subtitle {
        font-size: 16px;
    }
    
    .banner {
        height: 300px;
    }
    
    .login-container {
        flex-direction: column;
    }
    
    .login-image {
        width: 100%;
        height: 200px;
    }
    
    .purchase-float {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        border-radius: 0;
        padding: 15px 20px;
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .logo {
        width: 140px;
        font-size: 16px;
    }
    
    .auth-buttons {
        gap: 8px;
    }
    
    .btn {
        padding: 6px 12px;
        font-size: 12px;
    }
    
    .banner-title {
        font-size: 24px;
    }
    
    .banner-subtitle {
        font-size: 14px;
    }
    
    .section-title {
        font-size: 22px;
    }
}